Seasonal variability in diversity and abundance of the free-living pelagic copepod community of the Algerian coasts (SW Mediterranean Sea)

Crustaceana ◽  
2018 ◽  
Vol 91 (8) ◽  
pp. 913-946
Author(s):  
Mustapha Chaouadi ◽  
Aziz Hafferssas
Keyword(s):  
Species Richness ◽  
Seasonal Variability ◽  
Feeding Strategy ◽  
Hierarchical Classification ◽  
High Abundance ◽  
Copepod Community ◽  
Free Living ◽  
Pelagic Copepod ◽  
Ascending Hierarchical Classification ◽  
Centropages Typicus

Abstract Investigations on the free-living, pelagic copepod community of the Algerian coasts were performed at the Habibas Islands and in Bou Ismail Bay (Sidi Fredj coast) between 0 and 100 meter depth during various seasons of the year 2012-2013. Seventy-seven taxa at species level have been identified, belonging to 47 genera and 24 families. The distribution of the copepod community revealed seasonal variability; high abundance and species richness (greater than 20 species) characterized winter and spring, while the summer period was characterized by low abundance and species richness. The spatial distribution showed high abundance and species richness on the Sidi Fredj coast (the respective mean abundances along the Sidi Fredj coast and at the Habibas Islands were 253.71 ind.m−3 and 109.77 ind.m−3, respectively). Analysis of the samples showed the presence of seven abundant and frequent species: Centropages typicus, Eucalanus elongatus, Pleuromamma abdominalis, Paracalanus parvus, Paracalanus nanus, Calanus helgolandicus, and Temora stylifera. Multivariate analysis (ascending hierarchical classification and non-metric multidimensional scaling) enabled us to group the stations according to the composition in the copepod species, and the influence of seasonal changes was well observed. A dominance of herbivorous behaviour, followed by an omnivorous feeding strategy, was observed in the two studied areas. A dominance of epipelagic and epi-mesopelagic species was observed during all seasons, reflecting a neritic character of both study areas.

scholarly journals Diversity and distribution of the free-living freshwater Cyclopoida (Copepoda: Crustacea) in the Neotropics

2008 ◽  
Vol 68 (4 suppl) ◽  
pp. 1099-1106 ◽  
Author(s):  
WM. Silva
Keyword(s):  
Species Richness ◽  
Northern Region ◽  
Southern Region ◽  
Environmental Complexity ◽  
Free Living ◽  
Diversity Patterns

Cyclopoida species from the Neotropics are listed and their distributions are commented. The results showed 148 species in the Neotropics, where 83 species were recorded in the northern region (above upon Equator) and 110 species in the southern region (below the Equator). Species richness and endemism are related more to the number of specialists than to environmental complexity. New researcher should be made on to the Copepod taxonomy and the and new skills utilized to solve the main questions on the true distributions and Cyclopoida diversity patterns in the Neotropics.

scholarly journals The Provision and Accessibility to Parks in Ho Chi Minh City: Disparities along the Urban Core—Periphery Axis

Urban Science ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 37 ◽  
Author(s):  
Anh Hoang ◽  
Philippe Apparicio ◽  
Thi-Thanh-Hien Pham
Keyword(s):  
Geographical Information Systems ◽  
Hierarchical Classification ◽  
Spatial Accessibility ◽  
Geographical Information ◽  
Ho Chi Minh City ◽  
Urban Core ◽  
Different Types ◽  
Ascending Hierarchical Classification ◽  
The City

In Ho Chi Minh City (HCMC, Vietnam), there is now an urgent need for evaluating access to parks in an effort to ensure better planning within the context of rapid and increasingly privatized urbanization. In this article, we analyze the provision and accessibility to parks in HCMC. To achieve this, the information gathered was then integrated into the geographical information systems (GISs). Based on an Ascending Hierarchical Classification, we were able to identify five different types ranging in their intrinsic characteristics. The accessibility measurements calculated in the GISs show that communities are located an average of at least 879 meters away from parks, which is a relatively short distance. Children have a level of accessibility comparable to that of the overall population. Accessibility also seems to vary greatly throughout the City—populations residing in central districts (planned before 1996) enjoy better accessibility compared to those in peripheral neighborhoods (planned after 1996). Parks located in areas planned between 1996 and 2002 are the least accessible, followed by parks in areas planned after 2003. Our findings suggest possible approaches that could be used to help ensure the quality of parks and their spatial accessibility.

scholarly journals Ascending hierarchical classification for camera clustering based on FoV overlaps for WMSN

2019 ◽  
Vol 9 (6) ◽  
pp. 382-388 ◽  
Author(s):  
Ala-Eddine Benrazek ◽  
Brahim Farou ◽  
Hamid Seridi ◽  
Zineddine Kouahla ◽  
Muhammet Kurulay
Keyword(s):  
Hierarchical Classification ◽  
Ascending Hierarchical Classification

Does the Mesh Size of the Plankton Net Affect the Result of Statistical Analyses of the Relationship Between the Copepod Community and Water Masses?

Crustaceana ◽  
2011 ◽  
Vol 84 (9) ◽  
pp. 1069-1083 ◽  
Author(s):  
Chun-Ming Shin ◽  
Kuo-Ping Chiang ◽  
Chih-Jung Wu
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Mesh Size ◽  
Water Masses ◽  
Statistical Analyses ◽  
The East China Sea ◽  
Copepod Community ◽  
The Difference ◽  
The Relationship ◽  
Net Affect

AbstractWe examined if the results of statistical analyses of the relationship between copepod communities and water masses would be affected by the mesh size of the plankton net, by comparing abundance and species composition of copepods in plankton samples collected by plankton nets of different mesh sizes. Our samples were collected during the summer of 2006 in the East China Sea (ECS) by plankton nets with mesh sizes of 100 and 330 μm. The abundance of copepods collected by the 100 μm-mesh plankton net was about two orders of magnitude higher than that collected by the 330 μm-mesh plankton net. The difference in abundance was mainly due to the loss of small-sized copepods in the samples collected by the plankton net with the larger mesh. Species richness was higher in samples collected by the 100 μm-mesh net and Piélou's evenness was generally higher in samples collected by the 330 μm-mesh net. Although species composition of copepods varied in samples collected by plankton nets with different mesh sizes, the statistical analysis of the relationship between the copepod community and the water masses in these samples appeared not to be affected.

scholarly journals Evaluation of the Behavior of Cashew Genotypes with Regard to Bacterial Disease in Agroforestry Farms in Northern Côte d'Ivoire

2021 ◽  
pp. 106-117
Author(s):  
Brou Kouassi Guy ◽  
Diarrassouba Nafan ◽  
Doga Dabé ◽  
Oro Zokou Franck ◽  
Leki Konan Bertrand ◽  
...  
Keyword(s):  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Descriptive Analysis ◽  
Hierarchical Classification ◽  
Severity Index ◽  
Agroforestry System ◽  
Bacterial Disease ◽  
Cote D’Ivoire ◽  
Côte D'ivoire ◽  
Ascending Hierarchical Classification

Notwithstanding the inflows of currency for the populations who practice it, the cultivation of the cashew tree contributes to strengthening the forestry agrosystem in Côte d'Ivoire. However, this culture, with multiple interests, is confronted with attacks from parasites including bacterial disease. Bacterial disease causes extensive damage to vegetative organs as well as fruits and causes yield losses. The objective of this study is to assess the behavior of cashew genotypes in relation to the severity and incidence of bacterial disease in the context of agroforestry production in Côte d'Ivoire. To achieve this objective, 1.200 branches were observed to assess the tolerance or sensitivity of 30 cashew trees in agroforestry orchards of cashew trees in the localities of Korhogo, Sinématiali and Boundiali. These cashew genotypes were selected and geolocated. The factor studied is the cashew genotype, composed of 30 cashew genotypes, with 6 modalities which are the severity index of bacterial disease on leaves, twigs and nuts, the incidence of bacterial disease. bacterial disease on leaves, twigs and nuts. The data collected that are the index of severity of bacterial disease on leaves, twigs and nuts, the incidence of bacterial disease on leaves, twigs and nuts have made the subject to descriptive analysis and PCA. The ascending hierarchical classification (HAC) and multivariate analysis completed the data analysis. The results obtained revealed three groups of cashew trees. Those of group 3 made up of twelve (12) genotypes, namely SYDN, SDYY, SDYN and KBSD coming from the localities of Sinématiali and Korhogo, differ from the others by a weak infection of the nuts (8.67 ± 2.74). The genotypes in this group are more resilient and their development in an agroforestry system could help promote  agroecological management of bacterial disease, improve and intensify agroforestry practices in C. d'Ivoire.

scholarly journals Identification of Agromorphological Determinants Favoring the Propagation of Bacterial Disease in Agroforestry Farms of Cashew Trees in Côte d'Ivoire

2021 ◽  
pp. 29-37
Author(s):  
Brou Kouassi Guy ◽  
Oro Zokou Franck ◽  
Doga Dabé ◽  
Leki Konan Bertrand ◽  
Kouassi Koffi II Nazaire ◽  
...  
Keyword(s):  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Cropping Systems ◽  
Descriptive Analysis ◽  
Hierarchical Classification ◽  
Agroforestry Systems ◽  
Bacterial Disease ◽  
Cote D’Ivoire ◽  
Côte D'ivoire ◽  
Ascending Hierarchical Classification

In Côte d'Ivoire, cashew cultivation faces several health obstacles. Among these problems, bacteriosis causes extensive damage to twigs, leaves and fruits, lowers the quality of crops and causes yield losses. The spread of this disease would be under the determination of the morphological characters of the cashew tree. The objective of this study is to search for agro-morphological determinants that influence the spread of bacteriosis in agroforestry systems in Côte d'Ivoire. To achieve this objective, 30 cashew trees spread across 26 agroforestry cashew orchards in the Korhogo, Sinématiali and Boundiali departments were chosen and geolocated. The study factor is the clone, consisting of 30 cashew genotypes, with 13 modalities. The collected data was subjected to descriptive analysis, correlation test, ACP and ascending hierarchical classification (CAH). The results obtained showed that the size and leaf areas and size of cashew trees are determinants that promote the spread of bacteriosis in these 30 cashew genotypes. Following this result, the ascending hierarchical classification (CAH) made it possible to screen the genotypes into three groups. These results should contribute to the agroecological management of bacteriosis, to enhance and intensify agroforestry cropping systems in Côte d'Ivoire.

scholarly journals Particle-associated and free-living microbial assemblages are distinct in a permanently redox-stratified freshwater lake

2021 ◽  
Author(s):  
Ashley B. Cohen ◽  
Vanja Klepac-Ceraj ◽  
Kristen Butler ◽  
Felix Weber ◽  
Arkadiy I. Garber ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Seasonal Variability ◽  
Inorganic Nitrogen ◽  
Niche Partitioning ◽  
Green Sulfur Bacteria ◽  
Redox Conditions ◽  
Substrate Availability ◽  
Free Living ◽  
Sulfate Reducing ◽  
Green Lake

Microbial assemblages associated with biogenic particles are phylogenetically distinct from free-living counterparts, yet biogeochemically coupled. Compositions may vary with organic carbon and inorganic substrate availability and with redox conditions, which determine reductant and oxidant availability. To explore microbial assemblage compositional responses to steep oxygen and redox gradients and seasonal variability in particle and substrate availability, we analyzed taxonomic compositions of particle-associated (PA) and free-living (FL) bacteria and archaea in permanently redox-stratified Fayetteville Green Lake. PA and FL assemblages (> 2.7 μm and 0.2-2.7 μm) were surveyed at the peak (July) and end (October) of concurrent cyanobacteria, purple and green sulfur bacteria blooms that result in substantial vertical fluxes of particulate organic carbon. Assemblage compositions varied significantly among redox conditions and size fractions (PA or FL). Temporal differences were only apparent among samples from the mixolimnion and oxycline, coinciding with seasonal hydrographic changes. PA assemblages of the mixolimnion and oxycline shifted from aerobic heterotrophs in July to fermenters, iron-reducers, and denitrifiers in October, likely reflecting seasonal variability in photoautotroph biomass and inorganic nitrogen. Within a light-scattering layer spanning the lower oxycline and upper monimolimnion, photoautotrophs were more abundant in July than in October, when Desulfocapsa, a sulfate-reducing and sulfur-disproportionating bacterium, and Chlorophyte chloroplasts were abundant in PA assemblages. In this layer, microbial activity and cell concentrations were also highest. Below, the most abundant resident taxa were sulfate-reducing bacteria and anaerobic respirers. Results suggest PA and FL assemblage niche partitioning interconnects multiple elemental cycles that involve particulate and dissolved phases.

scholarly journals Temporal Variation of the Pelagic Copepod Community in Acapulco Bay, México

2016 ◽  
Vol 06 (01) ◽  
pp. 40-48 ◽  
Author(s):  
Agustín A. Rojas-Herrera ◽  
Juan Violante-González ◽  
Sergio García-Ibáñez ◽  
Salvador Villerías-Salinas ◽  
Giovanni Moreno-Díaz
Keyword(s):  
Temporal Variation ◽  
Copepod Community ◽  
Pelagic Copepod

scholarly journals Diversité Inter Décennale De La Végétation De La Vallée De Goulbi N’Kaba

2018 ◽  
Vol 14 (9) ◽  
pp. 161
Author(s):  
Mahaman Hamissou Illo Souley ◽  
Karim Saley ◽  
Issa Chaibou ◽  
Boubacar M. Moussa ◽  
Ali Mahamane ◽  
...  
Keyword(s):  
Beta Diversity ◽  
Hierarchical Classification ◽  
Stratified Sampling ◽  
Plant Biodiversity ◽  
Simpson Index ◽  
Dimensional Scaling ◽  
Plant Groups ◽  
Ascending Hierarchical Classification ◽  
Mixed Fields ◽  
Multi Dimensional Scaling

The present study is conducted in the Sylvo-Pastoral Zone (ZSP) of the Goulbi N'Kaba Valley and the agricultural zone (fields on adjacent terraces), in the southern center of Niger. The objective of the study is to evaluate the inter-decennial plant biodiversity (2004-2014). Thus, the phytosociological surveys (Daget and Poissonet, 1971) were carried out in plots of 2500 m², along the 6.5 km transects following stratified sampling. An ascending hierarchical classification, followed by an ordination by Nonmetric Multi-dimensional Scaling (NMS) allowed to identify the plant groups. The diversity of each group was evaluated. The results show that the families of Poaceae and Fabaceae are the most abundant in 2004 (15.58% and 11.69%) and in 2014 (18.75% and 7.29%). However, compared to the genera, Indigofera (10.53%), Cassia (6.58%), Acacia (5.26%), Aristida (5.26%) are the most abundant in 2004, while Aristida (4 , 17%), Cassia (4.17%), Spermacoce (3.13%), in 2014. Three groups (mixed, fields, ZSP) have been identified. The 2004 and 2014 index, of Margalef (18,38 and 11,28), Menhinick (2,55 and 1,52), Shannon-Weaver (4,77 and 4,14), the fairness of Pielou (0, 66 and 0.63), the Simpson index (0.89 and 0.91) and Hill (0.95 and 0.93) are high in all the groups, mixed, fields and ZSP (respectively for G1, G2 and G3). But the beta diversity (Whittaker (24), Jaccard (0.52), Sorensen (0.69) index) for each of these groupings remains low. There was no significant change in inter-decennial diversity at the Guidan Tawayé and Korin Habdjia sites from 2004 to 2014.

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